It has been known within the art that a prosthesis can be used for intraluminal repair of a vessel, such as an abdominal aorta having an aneurysm. The prosthesis, which can be a graft and/or a stent, is positioned and secured in a vessel, with hooks or staples that are self expanding or mechanically extended by a user into the lumen of the vessel. The orientation and position of the prosthesis relative to the vessel is very important to the success of the operation, and therefore methods have been used to view the prosthesis under fluoroscopy.
Precise orientation and positioning of an endovascular prosthesis within a vessel is critical to the success rate of repairing aneurysms. Endovascular prostheses are typically introduced into the vascular system of a patient within a catheter following over a guide wire and into position at the repair site. The positioning of the catheter and prosthesis is typically monitored under fluoroscopy. Once in position, the prosthesis will be expanded from a contracted configuration to an expanded configuration to engage the vessel lumen. The prosthesis is usually anchored into healthy tissue above and below the aneurysm, allowing the prosthesis to span the entire aneurysm preventing pressure from acting on the damaged area, and to prevent leakage through any rupture of the aneurysm. In order for the prosthesis to span the aneurysm properly, the prosthesis should be accurately positioned.
The radial orientation of the prosthesis is also important to prevent twists in the prosthesis. This is especially important when the prosthesis is a bifurcated graft. Each leg of the bifurcated graft should be aligned with its intended vasculature branch, or the body lumen may become distended and the lumen of the graft may be distorted and even closed completely. If the bifurcated graft is assembled in situ, it may be impossible to deploy a leg of the graft into a misaligned port of the graft. Recapture or repositioning of an expanded prosthesis can be problematic, therefore it is very important to correctly align the prosthesis in the vasculature system.
Previous attempts have used radiopaque markers attached to the endovascular implant to facilitate positioning of endovascular prosthesis inside corporeal vessels. However, previous attempts could not readily identify all twists in the implant. Further, with the previous attempts, it could be difficult to orient a portion of the implant because the radiopaque markers had a low contrast and the markers would change shape when viewed under fluoroscopy which projects a two-dimensional image of a three-dimensional prosthesis.
For these reasons, it would be desirable to have an endovascular prosthesis with high contrast imaging markers that are able to detect the position and orientation of the prosthesis using a two-dimensional screen for viewing.